Atmospheric water generator

ABSTRACT

An atmospheric water generator includes a refrigeration circuit having an evaporator coil and a condenser coil. The condenser coil is positioned proximate to the evaporator coil, and preheats a flow of atmospheric air as the air is forced through the condenser coil before the air passes through the evaporator coil. Liquid water condensate from the preheated air is generated as the air passes through the evaporator coil and is accumulated in a water collection tank. A second condenser coil cooled by a second flow of atmospheric air supplies refrigerant to the evaporator coil.

BACKGROUND

Water is a valuable resource which can be scarce in geographic regions which have extremely dry climates and few natural sources of fresh water. Even in such dry climates, however, the local atmospheric air typically contains at least some water in the form of water vapor. Accordingly, it would be desirable to have the ability to extract this available moisture from relatively dry atmospheric air to provide liquid water for drinking, food preparation, bathing, washing, irrigation, livestock, industrial applications, and other common uses. In particular, it would be beneficial to be able to extract substantial quantities of liquid water from atmospheric air having low relative humidity (for example, relative humidity less than or equal to about 35 percent). In addition, it would be helpful to be able to scavenge substantial volumes of liquid water from atmospheric air in cooler climates where atmospheric temperatures are relatively low (for example, locations where the air temperature is less than or equal to about 55 degrees Fahrenheit).

SUMMARY

One embodiment of an atmospheric water generator according to the invention includes a refrigeration circuit having an evaporator coil and a condenser coil. The condenser coil can be positioned proximate to the evaporator coil, and can be configured to preheat a flow of atmospheric air as the air is forced through the condenser coil and then through the evaporator coil. Liquid water condensate from the preheated air is generated as the air passes through the evaporator coil. The atmospheric water generator can also include a water collection tank configured to accumulate the liquid water condensate. In one arrangement, the evaporator coil and the condenser coil have corresponding non-flat shapes. The atmospheric water generator can further include a second condenser coil which is cooled by a second flow of atmospheric air and supplies refrigerant to the evaporator coil.

In another embodiment according to the invention, an atmospheric water generator includes a chassis and a refrigeration circuit within the chassis. The refrigeration circuit can include a compressor, a primary condenser coil, a secondary condenser coil, an expansion valve, an evaporator, at least one condenser fan, and at least one evaporator fan. The secondary condenser coil can be positioned proximate to the evaporator coil, and can be configured to preheat atmospheric air before the air is forced through the evaporator by the evaporator fan. Refrigerant can be supplied from the compressor to both the primary condenser coil and the secondary condenser coil, and liquid water condensate from the preheated atmospheric air is generated as the preheated air is forced through the evaporator coil. The condenser fan can be configured to force a first flow of atmospheric air through the primary condenser coil, and the evaporator fan can be configured to force a second flow of atmospheric air through the secondary condenser coil and the evaporator coil. The atmospheric water generator can also include at least one water collection tank configured to collect the liquid water condensate from the evaporator. At least one drain line can be provided to drain the liquid water condensate from the water collection tank, and at least one pump can be configured to pump the liquid water condensate from the drain line to a water storage location.

The atmospheric water generator can further include a divider panel which separates a condenser chamber and an evaporator chamber within the chassis. At least one dried air duct can be configured to direct dried air from the evaporator chamber to the condenser chamber. In addition, the condenser fan can be configured to exhaust both a first flow of air which passes through the primary condenser and the dried air which enters the condenser chamber from the evaporator chamber through the dried air duct. In one embodiment, the evaporator fan is located at one end of the dried air duct. The atmospheric water generator can also include a second water collection tank, and the dried air duct can be configured to direct dried air from the evaporator chamber into the second water collection tank. The secondary water collection tank can be arranged to collect liquid water condensate from the dried air. At least one dried air vent can be provided to permit the dried air to enter the condenser chamber from the second water collection tank. At least one of the primary condenser coil and the secondary condenser coil can have a non-planar shape.

The invention also includes a method of generating liquid water from atmospheric air containing water vapor. In one embodiment, the method includes providing a refrigeration circuit having an evaporator, preheating a flow of atmospheric air containing at least some water vapor, passing the flow of preheated air through the evaporator to cause liquid water to condense from the preheated air, and collecting the condensed liquid water. The step of preheating the flow of atmospheric air can include passing the flow of atmospheric air through a condenser coil of the refrigeration system before the air passes through the evaporator coil.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of an atmospheric water generator according to the present invention with portions of the outer chassis broken away to reveal internal components;

FIG. 2 is an exploded perspective view of the water generator shown in FIG. 1;

FIG. 3 is a schematic showing one embodiment of a refrigeration circuit for use in the water generator shown in FIGS. 1 and 2;

FIG. 4 is a graphical representation of a cross section of a water generator like that shown in FIGS. 1 and 2; and

FIG. 5 is a flow diagram showing a method of producing liquid water by condensing water vapor from atmospheric air.

DETAILED DESCRIPTION

One embodiment of an atmospheric water generator (AWG) 100 according to the invention is shown in FIGS. 1-4. As shown in FIGS. 1 and 2, the AWG 100 can include a substantially hollow chassis 105. In the embodiment shown in the figures, the chassis has a box-like shape with four substantially flat sides, a substantially flat top, and a substantially flat bottom. One side of the chassis 105 includes a first air intake grill 115 for admitting a first flow of atmospheric air into the chassis 105, and an opposite side of the chassis 105 includes a second air intake grill 104 for admitting a second flow of atmospheric air into the chassis 105. The second air intake grill 104 can include a filter (not shown) for preventing particulates and other debris and contaminates from entering the AWG 100 through the second air intake grill 104.

The AWG 100 further includes a primary condenser coil 114 located proximate to the first air intake grill 115. The primary condenser coil 114 is positioned within the chassis 105 such that the first flow of atmospheric air will pass through the primary condenser coil 114. In the embodiment shown in FIGS. 1 and 2, the primary condenser coil 114 has a non-planar “m-shape” to maximize the surface area of the primary condenser coil 114 within the confines of the box-shaped chassis 105. The primary condenser coil 114 can also have other shapes or configurations not shown in the drawings. In one embodiment, the primary condenser coil 114 has about 20 fins per inch. The AWG 100 also includes one or more condenser fans 113 a, 113 b. The condenser fans 113 a, 113 b can be positioned on top of the chassis 105 and inboard from the primary condenser coil 114 such that the condenser fans 113 a, 113 b draw the first flow of air through the first air intake grill 115 and the primary condenser coil 114, and then upwardly exhaust the first flow of air from the chassis 105. In one embodiment, the condenser fans 113 a, 113 b are enclosed to direct the first flow of air away from second air intake grill 104 as the first flow of air exits the chassis 105. The condenser fans 113 a, 113 b can include 70 degree Celsius direct drive motors, for example. As shown in FIG. 2, condenser intake grills 106 can be provided on each side of the chassis 105 to permit additional air flow into the condenser region of the chassis 105.

The AWG 100 shown in FIGS. 1 and 2 also includes an evaporator coil 103 located proximate to the second air intake grill 104. The evaporator coil 103 is positioned within the chassis 105 such that the second flow of atmospheric air passes through the evaporator coil 103 after entering the second air intake grill 104. In the embodiment shown in FIGS. 1 and 2, the evaporator coil 103 has a non-flat V-shape to maximize its surface area within the confines of the box-shaped chassis 105. The evaporator coil 103 can also have other shapes or configurations not shown in the drawings. In one embodiment, the evaporator coil 103 is a four-row microtube evaporator coil with about 20 fins per inch. As shown in FIGS. 1 and 2, the AWG 100 also includes a secondary condenser coil 101 located between the evaporator coil 103 and the second air intake grill 104. The secondary condenser coil 101 is positioned within the chassis 105 such that the second flow of atmospheric air passes through the secondary condenser coil 101 before passing through the evaporator coil 103. In the embodiment shown in FIGS. 1 and 2, the secondary condenser coil 101 also has a V-shape which corresponds to the V-shape of the evaporator coil 103. The evaporator coil 103 can also have other shapes or configurations not shown in the drawings. Preferably, the shapes of the secondary condenser coil 101 and the evaporator coil 103 are substantially the same such that they can be positioned closely proximate to each other or nested together within the chassis 105.

As further shown in FIGS. 1 and 2, the AWG 100 also includes a partition or divider panel 111 which separates the interior of the chassis 105 into two primary compartments or chambers. In the embodiment shown, the primary condenser 114 and condenser fans 113 a, 113 b are located on one side of the divider panel 111, and the evaporator coil 103 and secondary condenser coil 101 are located on the opposite side of the divider panel 111. A principal function of the divider panel 111 is to isolate the first air flow through the primary condenser coil 114 from the second air flow through the evaporator coil 103.

One embodiment of a refrigeration circuit 200 for use in the AWG 100 shown in FIGS. 1 and 2 is depicted in FIG. 3. In this embodiment, the circuit 200 includes a compressor 202, the primary condenser coil 114, an expansion valve 222, the evaporator coil 103, the secondary condenser coil 101, a liquid receiver 205, and an accumulator 230. These components are interconnected by a series of conduits, valves, regulators and controls, as discussed in detail below. Operation of the refrigeration circuit 200 can be controlled by a programmable logic circuit 120.

The primary flow path of refrigerant within the refrigeration circuit 200 is described beginning at the compressor 202. In one embodiment, the compressor 202 is scroll-type compressor. Hot gaseous refrigerant exits the compressor 202 at high pressure through a compressor discharge line 204 and passes to the primary condenser coil 114. As shown in FIG. 3, the compressor discharge line 204 can include a high pressure switch 244 configured to shut down the compressor 202 if excessively high pressure is detected in the discharge line 204 proximate to the compressor 202. In addition, the compressor discharge line 204 can include a check valve 207 to prevent the backflow of refrigerant to the compressor 202 through the discharge line 204, and a head pressure regulator 242 to restrict the pressure of the refrigerant delivered to the primary condenser 114. The refrigerant passes through the primary condenser coil 114 where it is cooled by air flow delivered by one or more condenser fans 113 a, 113 b. Condensed liquid refrigerant exits the primary condenser coil 114 at high pressure through primary condenser discharge line 212, and passes to a liquid receiver 205 through condenser discharge line 214. The primary condenser discharge line 212 can include a check valve 212 to prevent the backflow of refrigerant to the primary condenser coil 114. The liquid receiver 205 is configured to separate out any gas entrapped in the liquid refrigerant.

The refrigerant then passes through conduit 216 from receiver 205 to an expansion valve 222. Conduit 216 can include a filter drier 218 to remove any moisture or debris, and a sight glass 220 to permit observation of the condition of the refrigerant as it exits the filter drier 218. The refrigerant exits the expansion valve 222 as a cold low-pressure gas/liquid mixture and passes through evaporator supply line 224 to the evaporator 103. The refrigerant is heated as it passes through the evaporator coil 103 by air flow generated by one or more evaporator fans 112 a, 112 b, 112 c, and exits the evaporator coil 103 through an evaporator discharge line (suction line) 226 in a primarily gaseous state. The refrigerant then passes through the evaporator discharge line 226 to an accumulator 230 which prevents any liquid refrigerant from entering the compressor 202. The gaseous refrigerant is then returned to the compressor 202, and the refrigeration cycle is complete.

As can be seen in FIG. 3, the refrigeration circuit 200 also includes the secondary condenser coil 101 which is located proximate to the evaporator coil 103. Hot compressed gas refrigerant is supplied to the secondary condenser coil 101 through condenser bypass line 206 from compressor discharge line 204. Condenser bypass line 206 can include an in-line solenoid valve 208 to control the flow of refrigerant to the secondary condenser coil 101. Operation of the solenoid valve 208 can be controlled by a pre-programmed logic circuit (not shown) based upon various monitored system parameters. The hot gaseous refrigerant is cooled as it passes through the secondary condenser coil 101 by the same airflow that is forced through the evaporator 103 by the evaporator fans 112 a, 112 b, 112 c. Conversely, this air is heated as it passes through the secondary condenser coil 101 and before it reaches the evaporator 103. The refrigerant exits the secondary condenser coil 101 and is combined with refrigerant exiting the primary condenser coil 114 via secondary condenser discharge line 210. Accordingly, refrigerant from both the primary condenser coil 114 and the secondary condenser coil 101 pass through the expansion valve 222. As shown in FIG. 3, a line 225 can be provided between the compressor discharge line 204 and the evaporator supply line 224. The line 225 can include a compressor capacity control 240 and an isolator valve 250, and can be used to selectively direct hot gaseous refrigerant to the evaporator coil 103 in order to prevent the evaporator coil 103 from freezing up.

As the preheated atmospheric air passes through the evaporator coil 103, water vapor contained within the air condenses and accumulates under and around the evaporator coil 103. As shown in FIG. 3, this condensate is accumulated and drained to a main water tank 107 via a condensate drain 310. The main water collection tank 107 may be insulated. An ozonator 308 can be provided to sanitize the water as it resides in the tank 107. The main water tank 107 can include one or more float switches 306 to detect the level of water accumulated within the tank 107. Once a desired level of water has accumulated in the tank 107 and is detected by the float switch 306, the water can be automatically pumped from the tank 107 to a water storage location via a pump 304 and water transfer lines 302, 312.

As discussed above, atmospheric air is preheated by the secondary condenser coil 101 before the air passes through the evaporator coil 103. As a result, the AWG 100 is capable of extracting a substantially larger volume of water from a given mass of atmospheric air than would be possible if the air was not preheated. In addition, preheating the air permits the AWG 100 to be used to extract substantial amounts of liquid water from atmospheric air at relatively low atmospheric temperatures. For example, the AWG 100 can produce liquid water from atmospheric air at temperatures less than or equal to about 55 degrees Fahrenheit.

FIG. 4 illustrates the flow of air through the AWG 100. The arrows in FIG. 4 indicate airflow through the AWG 100. As shown in FIG. 4, a first flow of atmospheric air “A” is drawn into the chassis 105 through the first intake grill 115 and through the primary condenser coil 114 by condenser fans 113 a, 113 b. The heated air exits the primary condenser coil 114 and enters a condenser chamber 500 located between the primary condenser coil 114 and the divider panel 111. The air is then exhausted from the chassis 105 by the condenser fans 113 a, 113 b. Accordingly, the first flow of air “A” acts to continuously cool the primary condenser coil 114 as the AWG 100 operates.

On the opposite side of the chassis 105, a second flow of atmospheric air “B” is drawn into the chassis 105 through the second intake grill 104, through the secondary condenser coil 101, and through the evaporator coil 103 by evaporator fans 112 a, 112 b, 112 c. As best seen in FIG. 4, the evaporator fans 112 a, 112 b, 112 c can be positioned at the ends of one or more dried air ducts 110 which are configured to permit the dried air to exit the evaporator chamber 400 by passing through the divider panel 111. In one embodiment, the evaporator fans 112 a, 112 b, 112 c are low-profile axial fans. As the second flow of atmospheric air “B” exits the evaporator coil 103, the dried air enters the evaporator chamber 400. Liquid water which has condensed from the second flow of air “B” as the air passed through the evaporator coil 103 accumulates at the bottom of evaporator chamber 400, and is drained into the main water collection tank 107. The dried air within the evaporator chamber 400 is then drawn through the dried air ducts 110 by the evaporator fans 112 a, 112 b, 112 c, and is directed into a secondary water collection tank 108. The secondary water collection tank 108 can be configured to collect remaining liquid water from the dried air before the dried air enters the dried air vents 120. A second condensate drain line 352 can be provided to collect accumulated water from the secondary water collection tank 108. The secondary water collection tank 108 can be in fluid communication with the primary water collection tank 10 such that water can pass between the secondary water collection tank 108 and the primary water collection tank 10.

The dried air then passes out of the secondary water collection tank 108 through one or more dried air vents 120, and enters the condenser chamber 500. The dried air vents 120 can include adjustable airflow dampers 122 to regulate the flow of air exiting the vents 120. The dried air is then exhausted from the condenser chamber 500 by the condenser fans 113 a, 113 b together with the air exiting the primary condenser coil 114.

As shown in FIG. 5, the invention also includes a method 600 of collecting a substantial quantity of liquid water from atmospheric air. In this method, a refrigerating circuit having an evaporator coil is provided 602. Atmospheric air is preheated 604, and the preheated air is then forced through the evaporator coil 606 to cause liquid water to condense from the air. The condensed water is then collected 608.

The above descriptions of various embodiments of the invention are intended to illustrate particular aspects and elements of the invention. Persons of ordinary skill in the art will recognize that certain changes or modifications can be made to the described embodiments without departing from the scope of the invention. All such changes and modifications are intended to be within the scope of the appended claims. 

What is claimed is:
 1. An atmospheric water generator comprising a refrigeration circuit including an evaporator coil and a condenser coil, wherein the condenser coil is positioned proximate to the evaporator coil and is configured to preheat a flow of atmospheric air as the air is forced through the condenser coil and then through the evaporator coil, whereby liquid water condensate from the preheated air is generated as the air passes through the evaporator coil.
 2. An atmospheric water generator according to claim 1 and further including a water collection tank configured to accumulate the liquid water condensate.
 3. An atmospheric water generator according to claim 1 wherein the evaporator coil and the condenser coil have corresponding non-flat shapes.
 4. An atmospheric water generator according to claim 1 further comprising a second condenser coil, wherein the second condenser coil is cooled by a second flow of atmospheric air and supplies refrigerant to the evaporator coil.
 5. An atmospheric water generator comprising: a. a chassis; and b. a refrigeration circuit within the chassis, the refrigeration circuit comprising: i. a compressor; ii. a primary condenser coil; iii. a secondary condenser coil; iv. an expansion valve; v. an evaporator; vi. at least one condenser fan; and vii. at least one evaporator fan; c. wherein the secondary condenser coil is positioned proximate to the evaporator coil and is configured to preheat atmospheric air before the air is forced through the evaporator by the evaporator fan; d. wherein refrigerant is supplied from the compressor to both the primary condenser coil and the secondary condenser coil; and e. whereby liquid water condensate from the preheated atmospheric air is generated as the preheated air is forced through the evaporator coil.
 7. The atmospheric water generator according to claim 5 wherein the condenser fan is configured to force a first flow of atmospheric air through the primary condenser coil and the evaporator fan is configured to force a second flow of atmospheric air through the secondary condenser coil and the evaporator coil.
 8. The atmospheric water generator according to claim 5 further comprising at least one water collection tank configured to collect the liquid water condensate from the evaporator.
 9. The atmospheric water generator according to claim 8 further comprising at least one drain line to drain the liquid water condensate from the water collection tank.
 10. The atmospheric water generator according to claim 9 further comprising at least one pump configured to pump the liquid water condensate from the drain line to a water storage location.
 11. The atmospheric water generator according to claim 5 further comprising a divider panel which separates a condenser chamber and an evaporator chamber within the chassis.
 12. The atmospheric water generator according to claim 11 further comprising at least one dried air duct configured to direct dried air from the evaporator chamber to the condenser chamber.
 13. The atmospheric water generator according to claim 12 wherein the condenser fan is configured to exhaust both a first flow of air which passes through the primary condenser and the dried air which enters the condenser chamber from the evaporator chamber through the dried air duct.
 14. The atmospheric water generator according to claim 12 wherein the evaporator fan is located at one end of the dried air duct.
 15. The atmospheric water generator according to claim 12 further comprising a second water collection tank, wherein the dried air duct is configured to direct dried air from the evaporator chamber into the second water collection tank, and wherein the secondary water collection tank is arranged to collect liquid water condensate from the dried air.
 16. The atmospheric water generator according to claim 15 further comprising at least one dried air vent configured to permit the dried air to enter the condenser chamber from the second water collection tank
 17. The atmospheric water generator according to claim 5 wherein at least one of the primary condenser coil and the secondary condenser coil have a non-planar shape.
 18. A method of generating liquid water from atmospheric air containing water vapor, the method comprising: a. providing a refrigeration circuit having an evaporator; b. preheating a flow of atmospheric air containing at least some water vapor; c. passing the flow of preheated air through the evaporator to cause liquid water to condense from the preheated air; and c. collecting the condensed liquid water.
 19. The method of claim 18 wherein preheating the flow of atmospheric air comprises passing the flow of atmospheric air through a condenser coil of the refrigeration system before the air passes through the evaporator coil. 